The pairing of the rather preachy passage from Galatians and the parable of the ten lepers from Luke at first seems an odd one. Jesus’ point – that none of us appreciate enough the gifts of God, since only the Samaritan thanks him for being cured – is really in line with the idea that living by the spirit is the only way to avoid sin in our lives. What is for most people the “straight and narrow” clearly means to Jesus the fullness of all experience.That sense of abundance is evident throughout Cantata BWV 17. The opening chorus, based upon the last verse of Psalm 50, is one of the richest and most brilliant of Bach’s choral fugues. There is nary a hint that this verse comes at the end of one of the severest and most unremittingly stern Psalms. The long opening ritornello is so lacking in profile, really only a little figure that is played in sequence over and over, that the entrance of the big high-flying tenor theme in bar 28 comes as a relief. Verticality is established on the words, “thanks” and “offering.” Horizontal writing prevails in the word “praise.” These two styles of melisma are identifiable throughout the cantata. The minimalist introduction is, of course, carefully calculated by Bach to bring this bravura choral theme into high relief, We have seen how the third Jahrgang is notable for its marvelously integrated choral fugues. Here there is no real necessity for that kind of integration; the choral music is so much more in the foreground than the orchestration. This is a fugue that neither has nor needs elaborate stretti or other contrapuntal wizardry. The working out is simple and straightforward, the episodes clear, even boxy. It makes its effect by brilliance and a wonderful rhythmic drive that propels it in a compellingly clear manner through the final cadence.
The lofty secco alto recitative has a grandeur that is in opposition to the humility of the following aria. It is interesting that all of the recitatives in this cantata have a tone noticeably absent in the concerted music. The rising scale passages that we heard throughout the first part of the chorus are again evident in the soprano aria. The two solo violins with the child soprano voice gives the aria a miniature quality in contrast to the opening chorus, but much of the material is basically the same. There is lightness, almost humor, here in the childish efforts at praise.The tenor recitative is unique in all of the cantatas in that it sets part of the Gospel as a pure secco recitative, no arioso, no string accompaniment. The tenor aria again emphasizes abundance. The main theme is cut from the same cloth as the chorus and the soprano aria, but is enriched by a detailed and interesting bass line. The shape of the melody is unusually specific to the character of the words. “Übermass” is set refulgently, the “offering” is horizontal. For all of the very detailed dissection of the text throughout the aria, this distinction of the two types of writing remains. There is a wonderful plasticity of phrasing; often the voice goes its own way against the more rigorous orchestra.Bach finds remarkable richness of harmony in the long and very diatonic choral “Nun lob mein Seel, den Herren.” The chromatic bass line in the last two phrases in particular is surprising and satisfying.